Nitrocellulose lacquer thinner



Patented Dec. 8, 1931 'IN'DIANA, A CORPGE-AEIODIOF MARYLAND- f v nitrrnoonntnnosn LA QiIER :T H innisn f.

Our invention relates toja method of makiii-g thinners suitable for LlSG'WllEl'l nitrocellu lose lacquers and particularly a thinner con t ining-butyl acetate ethyl acetate, ethyl alc'ohol, butyl alcohol and toluol.

Nitrocellulose lacquers containing fairly h'gh proportions of pigments cannot readily beshipped in the form in Which they are used;- because the pigments and'gums tend to settleout in-the' bottom'of the container and it is "rather difiicult to get them back into" solution'again With the'assuranc'e' that'no undissolved solid lumps or particles that would mar the'finished surface Will be present. For

this reasonautomobile lacquer is generally. shipped as a heavybase lacquer'yso thick and Viscous that its'constitue'nts will 'notordi narily separate thru the influence of gravity.-

This materiah-is'then thinned at the plant cientliydrocarbon I "anon-solvent tor nltrocellulose, the: ildCll-i tion of thinner to'thelacquer may cause the.

' Where it is tobe used With a thinner composedof suitable mixture ofsolvent and nonsoh'en't materials,

composed of, solvent materials' 'Tlie liquids empl ed for dilating a lacquerto the'prope-r consistencyforfapplication contain, in most c,ases, either coal tar of petroleum hydrocarbons,bothfgroups of which materials are nonrsolv-entsfor nitrocellulose. Altho other factors. als'ofcoine into consideration; itjis highly important that the: thinner composi' treat a' solvent for nitrocellulose, regard;- less ofthe composition of the mixed lacquer andthinnerp If the thinner contains sulhor diluent to make the mixtn precipitation orfmtroteliuio'se 'Which. is re dissolved; only \yitlrconsiderable di fii'cultyL ltii'sg' equally important that the arious solvents and non-solvents used in the produc-" tion of a lacquer thinner be present lin the proper proportions and also haye the proper rate ofeyaporation. It is obvious thati f the solvents present a lacquer eyaporate at much faster rate than do the non-solvents,

the lacquer or drying film. Should an e cessof non-solvent occur atany time'befoi'efthe onovnn BLooMrmLn, JEROME MARTIN, ANDIGNACna-KRCHMA; or 'irnnmi Jaimie}. .z-r' i INDIANA, ASSIGNOBS To, COMMERCIAL soLv'ENTs, communion-1,01 PIERRE HAUTE,

film has dried,theprecipitation ofnitrocellulose Will result, "giving; general, an uni satisfactory'finishf ,4 i

' Another familia phenomenon also. occurs ifthe thinner does not contain the proper" solyent in the properpr0portionsfiIThis phenomenon, known as" blushing; occurs.

when nioisture is condensed upo'n'the WQl'k under humid conditions, or fconve'rsely,whe'nl some of the moisturepresent in the original lacquer is notc'arried off. In orderto-prevent blushing, the thinner shouldf be' made of liquids of reasonably slow rate of eVap'O'ra' -j tion and preferably, no tmiscible With Water,- Thlnners meeting the above requirements and having approximately the" following composition have-been Very generally used in the industry 11125 70 ethyl acetate to but ylacetate, 1 0 to 20% butyl alcohol, and" 20 to diluent." The i diluentihas usually been to'luol but maybe substituted in part or Wholly by other hydrocarbons such as'xylol or V. M.;P; naphthafi A thinner equally as satisfactory frointhe V standpointof blushing and'at the same time somewhat less expensive "may be obtained by substitut ing ethylalcoho'l for a portion "of the ethyl v a'cet'atel Our invention pert'a'insftda novel process of preparing such] a' thinner',' at considerably' lower costs than by any previous method. Our' process may be'fully' understood "from the. following? description. The first step in'our new; process of preparing lacquer thinners involves the prepara-' ti on "of 'an'jappro xim'ately- 50% solution of ethylacetate ine'thyl alcoholJThis may be done by niixing appropriate quantities of commercial ethyl acetate and ethyl alcohol."

We prefer; however, to prepare Ztheethyl acetate-ethyl alcohol mixture by the method descrihedin a corpending application; Serial 1 278,333, filed 'May 16', '1 928 for preparing; ethyl acetate by passing'ethyl alcohol over a suitable-catalyst, the resulting product co'na sistin'g of 8 15%' ethyl .acetate and 92- 85% ethyl alcohol. The concentration of the ethyl acetate tothe desired strength'may be effected in several ways. For example, water may be added to the ethyl acetate-ethyl alcohol mixture and theresul-ting solution, subjected, to distillation, In this manner a; distillate containing approximately 50% or more ester may be Obtained by one fractionation. Another method: of effecting thedesiredi concentrationoftheethyh acetate is b-y-the addition of water and ahigh-boiling hydrocarbon such as Xylol or mesitylene to theethyl acetate-ethyl alcohol mixture. The resulting mixture after agitation separatesv into two separate layers, the water layer containing the 'greater'portionot the ethyl alcohol. andthe hydrocarbon layer, thegreaterportio-n of, the ethyl, acetate; The latter may then; be separated from the hydrocarbonby fractional distillation;

After thepreparationof the ethyl acetate? ethyl, 410611 1; solution by any of the methods described above, we proceed as follows.v Reflux for ',to,3 hours,: a mixture composed approximately of: volume butyl alcohol;

' 2.5. volumes. of a mixture which is approxihol; 3 volumes ,toluol 4 volumes water; 0.6]

mately 50%ethylacetate and.50% ethylialcovolume a concentrated sulphuric acid (cata- Duri' t g the-course of the refluxing,

holysis takes place resulting in the formation of butyl acetate and, ethvl'alcohol from the butyl; alcohol and, ethyl acetate At the. coil.-

- clusionof therefluxing, the .reactionproducts se arate intotwo senaratela ers of ii uids the'butyl; acetate, ethyl acetate, and, butyl. alcohohas well as a smaller amount of ethylv the/water layer containing the, greater poi;-

tion ofthe ethyl alcohol and. smaller por-. The

tions oi the other materials present. t oluol layer contains; the greater portion of alcohol The two layers of; liquids are separatedgand, subjected to fractional distillat-ion. By, di -stilling approximately. 10 20 Qf-thje tpluel layera mixture, partlyof con-. stant; boiling composition and, composed of:

toluol, Water,ethyl;alcoholand ethyl acetate is ramme v n app xima ly v volumes,- ofdry liquid" having approximately the 't'ollowi-ng composition; butyl acetate 20%, ethyl: acetate ethyl alcohol 5%, hntyl alcohol;5j%,toluol 65%. The materials removed;by'distillation from both the Water layer-andthe toluol layer may be recovered, ,andag'ain usedin the process with theresult thatthej losses. occurring during the operation arencglie bl 1 It is distinctly understood that the lacquer: thinner;described above iscited only as an eX.-.

' ample ot'compositionsof; a similar character whi hmay belprepared by. our new process, The relative amounts of: the final product described; abQVe} may; be varied somewhat byv a y ng h r mounts t h -ma al s antes alcoholwilhafter refluxing, be in the hydro carbon layer;v In the place of toluol, we may use xylol or petroleum hydrocarbonsuch as VIM. P'. naphtha; In place of ethyl" acetecs e s-d he w s an i iothen t engly water-soluble; alcoholsmay} be used, on an,

ester may-be used, alone. since howevler iti is; simpler toz prepare an esten-alcoholmix ture than a pure esten, the-vstanting; material;

Will, as a rule, consist of the formen, 'It should be pointed out, howeveiythatit it-is; found desinable ton any reason to ehangebne of the. constituents of the reactionfni-ixture,

it will in; most cases be A necessary to; alsothe characten of one or moreof -there inainin-g constituents in order thatthe laciqnen thinner to be! producect will, be properly; bal

anced as to rate. ofevaporatioin etc;jVSlemay-also employ other sub tances j han silk 7 phur c a d as the c t y t o fec ng e reaction, as for example, hydrochloric 5 acid} Q phesphQr cc i Now havingdescribedour inwantiomwhat.

we claim is; v v I 1, The process-of'preparing-a lacquer thin;

ner which comprises reacting, analcoholwith.

an'ester in thepresencc of the alcohol, of; the

said; ester, hydrocarbon, and water iQQE-V ering; the. resultinghydrocarbon, layem and finallyremovinglthe-water fromthe'said by;

drocarbon layer,lby distillation, asapart (if? a constant boilinganixture.

2,; Theprocess oipreparinga lacquer. thin; h-i mpr s eac ng a eaklawae ter-solublealcohol with an ester of a, strong- 1.

lywater-soluble alcohol; in, the presence of,

' he lQ hQL 0f h said. ester, a ydre arbom and, Water; recovering the resulting l y lro arb n layer d n llym ving he wa: ter from the said hydrocarbon layer, by dis;

'tillation, as apart-0 f a,constantrboilingfmix 3. The process ofpreparingalacquer thine ner which, comprises. reacting: an; alcohol, 29

with f an esterin thepresence of wateriand; a,.

hydrocarbon; recovei-ing, the resulting y hy; drocarbon layer; a'nd1 finally removing. the Water from the said" hydrocarbon layer, by distillation, as apart of a, constant-boiling. mixture 4. The process otprepziringalacquer thin: nen which comprises reacting a weakly vaa uter -soluble alcohol with anest'e'r, inthe pre ence ofwater and ahydrocarbon; recovering,

the resulting hydrocarbon layer; and finally removing the Water from the said hydrocarbon layer, by distillation, as a part of a constant-boiling mixture.

5. The process of preparing a lacquer thinner which comprises reacting butyl alcohol with ethyl acetate in the presence of ethyl alcohol, water, and a hydrocarbon; recovering the resulting hydrocarbon layer; and finally removing the Water from the said hydrocarbon layer, by distillation, as a part of a constant-boiling mixture.

6. The process of preparing a lacquer thinner which comprises reacting butyl alcohol with ethyl acetate in the presence of ethyl alcohol, Water, and toluol; recovering the resulting toluol layer; and finally removing the water from the said toluol layer, by distillation, as a part, of a constant-boiling mixture. I l

7. The process of preparing a lacquer thinner which comprises refluxing a mixture comprising one volume butyl alcohol, tWo and one-half volumes, approximately, 50%

ethyl acetate in ethyl alcohol, three volumes toluol, four volumes water, and six-tenths volume concentrated sulphuric acid; recovering the resulting toluol layer; and finally removing the water from the Said toluol layer, by distillation, as a part of a constant boiling mixture.

8. The process of preparing a lacquer thinner which comprises refluxing a mixture comprising one volume butyl alcohol, two and one-half volumes, approximately, 50% ethyl acetate in ethyl alcohol, three volumes toluol, four volumes Water, and six-tenths volume concentrated sulphuric acid, recovering the resulting toluol layer; and finally removing the water from said toluol layer by distilling 05 10 to 20% of the mixture.

In testimony whereof We afiix our signatures.

GROVER BLOOMFIELD. JEROME MARTIN. IGNAGE J. KBCHMA. 

